Weatherable and durable coating compositions

ABSTRACT

A curable coating composition is provided having multi-functionalized acrylic copolymer and amino-functional silicone resin curing agents. The acrylic copolymer of the curable coating composition has, in polymerized form, epoxy functionalized groups and cure compatibility groups and the amino-functional silicone resin is an aryloxy-containing amino-functional siloxane, which optionally is derived from sterically hindered alcohol-amine precursor moieties. The coating compositions are useful in the field of superior weatherable and durable coatings and are useful to replace isocyanate-containing polyurethane based coatings. Also provided are coated articles produced from the curable composition.

This invention relates to curable coating compositions havingmulti-functionalized acrylic copolymer and amino-functional siliconeresin curing agents. More particularly the acrylic copolymer has, inpolymerized form, epoxy functionalized groups and cure compatibilitygroups and the amino-functional silicone resin is an aryloxy-containingamino-functional siloxane, which optionally is also derived fromsterically hindered alcohol-amine precursor moieties. The coatingcompositions are useful in the field of superior weatherable and durablecoatings and are useful to replace isocyanate-containing polyurethanebased coatings.

Isocyanate-containing polyurethane based coatings are used inapplications where superior weatherability and durability are required.However, manufacturers and consumers desire to move to isocyanate-freecoatings to limit exposure to such materials; while providingweatherability in addition to chemical and corrosion resistance. Inapplications where epoxy coatings are used to protect metal, but requiregood color and gloss retention, the epoxy coatings are further coatedover with a topcoat, often a polyurethane. Other coatings derived fromepoxy resins, such as polysiloxane-epoxy coatings, are dependent onhumidity for cure and often become brittle as the coating continues tocure.

Some amino-functional polysiloxanes with amine functionality alsoincorporate aryl-containing groups, such as phenyl groups, to improveperformance attributes of the coating and compatibility of the coatingcomponents. Amine functional groups can be attached through Si—C and/orSi—O—C bonds; though attachment through Si—O—C bonds typically exhibitstability concerns in the presence of moisture, as the SiOC bond issusceptible to hydrolysis resulting in regeneration of the originalamine alcohol and silanol. Hydrolysis affects both the appearance of theprotective coating, as the alcohol amines are typically not compatiblewith the host siloxane resin and organic epoxy hardener, and theperformance of the protective coating, as the level of chemicalcross-linking will be greatly limited if the SiOC bond is severed.Aryl-containing groups, such as phenyl groups, are typically attached tothe polysiloxane through high cost Si—C bonds.

United States Patent Publication 2005/0148752 A1 disclosesamino-functional polysiloxanes possessing a Si—O—C bond between thepolymeric backbone and the functional group; and includesepoxy-polysiloxane compositions. US2005/0148752 A1 fails to identifycoatings comprising acrylic copolymers. Moreover, US2005/0148752 A1fails to distinguish benefits associated with use of siloxanes derivedfrom sterically hindered alcohol-amine precursor moieties fromnon-sterically hindered moieties.

U.S. Pat. No. 8,012,543 discloses use of polyorganosiloxanes modifiedwith amino alcohol for reducing corrosion on reinforcing steel ofconcrete constructions where the polyorganosiloxanes can comprise alkylor aryl radicals, including phenyloxy radicals. U.S. Pat. No. 8,012,543fails to identify coatings comprising acrylic copolymers.

United States Patent Publication US 2017-0174938 A1 discloses use of acoating layer composition containing a silsesquioxane composite polymerto prevent substrate warpage, where some embodiments of thesilsesquioxane composite polymer contain SiOC amine and SiOC arylgroups. US2017-0174938 A1 fails to identify coatings comprising acryliccopolymers.

U.S. Pat. No. 8,193,293 discloses a low temperature, ambient curablecoating composition comprising an amino-functional polysiloxane; apolysiloxane resin which is the reaction product of a polysiloxanecontaining silicon hydride and a hydroxyl functional group-containingmaterial having two or more unsaturated bonds capable of undergoinghydrosilylation reaction; and a polyepoxide.

U.S. Pat. No. 8,871,888 discloses a high solids, one-component, storagestable coating composition comprising an epoxy resin comprising morethan one 1,2-epoxy groups per molecule; a hydrocarbon compound having asoftening point of from 50° C. to 140° C.; an alkoxy-functional and/orsilanol-functional silicone; and a ketimine curing agent comprising areaction product of reactants comprising a polyalkyldiamine componentand a ketone component.

International Patent Publication WO 01/51575 A1 discloses an ambienttemperature curing coating composition comprising a polysiloxane withalkyl, aryl, alkoxy, reactive glycidoxy and OSi(OR)₃ groups; aglycidyl-functional acrylic polymer; and a hardener. The polysiloxanedoes not contain amine functionality.

Japanese Patent Publication 2002-167546 A discloses a corrosion proofcoating material composition for single-coating finishing comprising (A)an acrylic resin, (B) an epoxy resin having at least two epoxy groups,(C) an organosilane compound, and (D) an aminosilane-containing aminecuring agent, and as the compounding ratios of the acrylic resin (A),the epoxy resin (B) and the organosilane compound (C), the component (A)is 5-65 wt. %; the component (B) is 30-90 wt. %; and the component (C)is 5-65 wt. %, each based on the total amount of the solid contents ofthese resins.

What is needed is a cost effective coating composition that exhibitsgood stability in the presence of moisture and offers a good balance ofproperties including UV protection, corrosion resistance, good dry timesand chemical resistance; all while using a minimum of materials.

The present invention provides a curable coating composition comprising:

(1) an amino-functional silicone resin comprising in polymerized form,structural units of:

(i) (R₃SiO_(1/2))_(a);

(ii) (R₂Si(OR′)_(x)O_((2-x)/2))_(b);

(iii) (RSi(OR′)_(y),O_((3-y)/2))_(c); and

(iv) (Si(OR′)_(z)O_((4-z)/2))_(d);

wherein each R′ is independently hydrogen, an alkyl group, afunctionalized alkyl group, an aryl group or a functionalized arylgroup, provided that at least 10 mole percent of all R′ groups are arylgroups or functionalized aryl groups; wherein each R is independentlyhydrogen, an alkyl group, or a functionalized alkyl group; wherein atleast 10 mole percent of the combination of R and R′ groups are aminecontaining groups of the formula: —R_(a)—NHR_(b) where R_(a) is an alkylgroup or an aryl-containing group derived from an amino alcohol andR_(b) is hydrogen or an alkyl group; wherein a+b+c+d=1.00 (100 molepercent); x is either 0 or 1; y is either 0, 1 or 2; and z is either 0,1, 2, or 3; and the —NH— equivalent mass of the amino-functionalsilicone resin is from 50 to 750; and (2) an acrylic copolymer whichhas, in polymerized form, epoxy functionalized groups and curecompatibility groups; and wherein the coating composition has a molarratio of amine NH functionality to epoxy functionality in the range offrom 0.5 to 1.3. The present invention further provides a coated articlecomprising one or more layers of the cured coating composition.

The term “mole percent” can also be represented as a “mole fraction”whereby 1 mole percent equals a mole fraction of 0.01. The terms “molepercent” and “mole fraction” are on a basis of Si content in a materialtotaling 100 mol % (i.e. 1.00 mole fraction). For each range presentedin the present invention, the lower limit of the range and the upperlimit of the range are separable and combinable in any fashion withother lower or upper limits; including in combinations with the lowerand upper limits for the ranges of additional components identified inthe present invention. All individual values and subranges are includedherein and disclosed herein.

Amino-Functional Silicone Resin

The amino-functional silicone resin of the present invention can bedescribed as a siloxane structure having siloxane bonds (—Si—O—Si—)with: aryl functionality attached through Si—O—C bonds to Si units onthe siloxane structure; and amine functionality attached through eitherSi—O—C bonds to Si units on the siloxane structure or Si—C bonds to Siunits on the siloxane structure or some combination of the two, andcomprises in polymerized form, structural units of:

(i) (R₃SiO_(1/2))_(a);

(ii) (R₂Si(OR′)_(x)O_((2-x)/2))_(b);

(iii) (RSi(OR′)_(y),O_((3-y)/2))_(c); and

(iv) (Si(OR′)_(z)O_((4-z)/2))_(d)

wherein each R′ is independently hydrogen, an alkyl group, afunctionalized alkyl group, an aryl group or a functionalized arylgroup, provided that at least 10 mole percent of all R′ groups are arylgroups or functionalized aryl groups;

wherein each R is independently hydrogen, an alkyl group, or afunctionalized alkyl group;

wherein at least 10 mole percent of the combination of R and R′ groupsare amine containing groups of the formula: —R_(a)—NHR_(b) where R_(a)is an alkyl group or an aryl-containing group derived from an aminoalcohol and R_(b) is hydrogen or an alkyl group;

wherein a+b+c+d=1.00 (100 mole percent); x is either 0 or 1; y is either0, 1 or 2; and z is either 0, 1, 2, or 3; and

the —NH— equivalent mass of the amino-functional silicone resin is from50 to 1000, preferably 50 to 750, more preferred 80 to 900, even morepreferred 100 to 800, and most preferred 100-700.

R and/or R′ groups can be amine containing groups of the formula:—R_(a)—NHR_(b). The amount of all R and R′ groups which are aminecontaining groups of the formula: —R_(a)—NHR_(b) can be as low as 10mole percent or 20 mole percent and can independently be as high as 90mole percent, 50 mole percent or 30 mole percent, with preferred rangesof 10 to 42 mole percent and 20 to 30 mole percent; provided that the—NH— equivalent mass of the amino-functional silicone resin is withinthe identified ranges. R_(a) is derived from an amino alcoholrepresented by the formula HO—R_(a)—NHR_(b), wherein R_(a) is an alkylgroup or an aryl-containing group. Preferably R_(a) is derived from anamino alcohol which is selected from the group of amino alcohols which(a) have steric hindrance around the COH moiety; (b) are secondary ortertiary alcohols; or (c) are mixtures thereof.

The amount of all R′ groups which are aryl groups or functionalized arylgroups can be as low as 10 mole percent or 20 mole percent and canindependently be as high as 100 mole percent, 50 mole percent or 30 molepercent, with preferred ranges of 10 to 60 mole percent and 20 to 50mole percent.

In describing silicone resins, R₃SiO_(1/2) is also referred to as M,R₂SiO_(2/2) is also referred to as D, RSiO_(3/2) is also referred to asT, and SiO_(4/2) is also referred to as Q. In the event a superscript isused next to the M, D, T or Q designations, it refers to the type of Rgroup(s) present. For example, D^(Ph) mean that one of the two R groupsis a phenyl group. Any R group(s) not described by superscripts is to beunderstood by those skilled in the art as being methyl groups, unlessthe specific description of the polymer indicates otherwise. The —NH—equivalent mass of the amino-functional silicone resin is determined byobtaining a ¹³C-NMR spectrum of a known amount of solution of, or neatsample of, the amino-functional silicone resin and quantifying the peaksassociated with the amino-functional Si units of the amino-functionalsilicone resin relative to those associated with a known amount of aninternal standard (typically 1,4-dioxane), then adjusting for solventcontent present in the sample, if any, as determined by gaschromatography. The amino-functional silicone resin is in the form of aneat liquid, solution, or meltable solid. Each subscript a, b, c or d isan average value across the distribution of units making up the materialand is determined for any given material by using calculations based onNMR spectroscopic data (typically ²⁹Si-NMR and ¹³C-NMR, alternatively²⁹Si-NMR and ¹H-NMR).

The amino-functional silicone resin of the present invention can beproduced by reacting (1) a silicone resin having hydroxy or alkoxyfunctionality with (2) an amino alcohol and aryl alcohol. The siliconeresin having hydroxy or alkoxy functionality can be derived frompolysiloxanes, alkoxysilanes, or chlorosilanes. The hydroxy or alkoxyfunctionality of the silicone resin (1) composition is sometimesreferred to as the “OZ” content and is stated in terms of mole percent.Non-limiting examples of suitable silicone resins include DOWSIL™ 2403,DOWSIL™ 3074 and DOWSIL™ 3037, available from The Dow Chemical Company;Shin-Etsu Silicone KR-213 and KR-510, available from Shin-Etsu ChemicalCo., Ltd.; and SILRES® IC232 and SILRES® SY231, available from WackerChemie AG.

The amino alcohol can be represented by the formula HO—R_(a)—NHR_(b), aspreviously described. Non-limiting examples of suitable amino alcoholsinclude 2-amino-1-ethanol, 1-amino-2-propanol,1-amino-2-methylpropan-2-ol, 2-amino-1-propanol, 3-amino-1-propanol,2-amino-1-butanol, 3-amino-1-butanol, neopentanolamine(3-amino-2,2-dimethyl-1-propanol), 2-amino-1-methyl-1-propanol,2-amino-2-methyl-1-propanol, 2-amino-2-ethylpropane-1,3-diol,2-amino-2-methylpropane-1,3-diol, 5-amino-1-pentanol,1,2-dimethylethanolamine, 3-alloxy-2-hydroxy-propylamine,1-amino-2-methyl-pentanol, N-methylethanolamine,N-hydroxyethylpropanediamine, N-cyclohexylethanolamine,p-(beta-hydroxyethyl)-aniline,N-(beta-hydroxypropyl)-N′-(beta-aminoethyl)piperazine,2-hydroxy-3-(m-ethylphenoxy)propylamine, 2-hydroxy-2-phenylethyl amine,tris(hydroxymethyl)aminomethane, 2-aminobenzyl alcohol, 3-aminobenzylalcohol, 3-amino-o-cresol, 4-amino-o-cresol, 5-amino-o-cresol,2-amino-p-cresol, 4-amino-m-cresol, 6-amino-m-cresol,1-amino-1-cyclopentane methanol, 2-(2-aminoethoxy)ethanol,2-(2-aminoethylamino)ethanol, 6-amino-1-hexanol,3-(1-hydroxyethyl)aniline, 2-amino-1-phenylethanol,1-aminomethyl-1-cyclohexanol, 8-amino-2-naphthol, 2-amino-phenethylalcohol, 4-aminophenethyl alcohol, 3-(alpha-hydroxyethyl)aniline,Mannich bases, the reaction product of an aminoalcohol withcis-2-pentenenitrile followed by an hydrogenation step, aminophenolssuch as p-aminophenol, tyrosine, tyramine and the like, epoxy-amineadducts and mixtures thereof. Preferred amino alcohols include withoutlimitation, 1-amino-2-propanol and 1-amino-2-methylpropan-2-ol.

NMR: The compositions of the various aryloxy-containing amino-functionalsilicone resin compositions are determined utilizing NMR. The nuclearmagnetic resonance (NMR) analysis is done using a Mercury 400 MHz superconducting spectrometer. The instrument uses a silicon-free probe.

Aryloxy Content—Aryloxy content is calculated from 13C NMR data usingdeuterated chloroform as an internal standard. Using the weights ofresin and chloroform added to the NMR sample, the weight % aryloxy isdetermined. The molar amount of aryloxy is calculated using thisinformation in conjunction with the composition obtained from ²⁹Si NMR.

Molecular Weight—Resins that are analyzed for molecular weight (Mn andMw) are done using gel permeation chromatography. The samples areprepared in THF at 05% concentration, capped with acetic anhydride,filtered and analyzed against polystyrene standards using RI detection.The columns are two 300 mm 5 micrometer Mixed C with a 50 mm guardcolumn. The flow rate is 1 ml/min.

The alkyl groups are illustrated by, but not limited to, methyl, ethyl,propyl, butyl, hexyl, octyl, decyl, dodecyl, hexadecyl, and octadecylwith the alkyl group typically being methyl. The aryl groups areillustrated by, but not limited to, phenyl, naphthyl, benzyl, tolyl,xylyl, xenyl, methylphenyl, 2-phenylethyl, 2-phenyl-2-methylethyl,chlorophenyl, bromophenyl and fluorophenyl with the aryl group typicallybeing phenyl.

The silicone resin having hydroxy, alkoxy or aryloxy functionality issynthesized according to polymerization methods known in the art.Non-limiting, illustrative polymerization methods are disclosed inUnited States Patent Publication 2005/0148752 A1.

Multi-Functionalized Acrylic Copolymer Description

The multi-functionalized acrylic copolymer means a copolymer including amajority amount of copolymerized (meth)acrylic esters, including inpolymerized form through the acrylate linkages, epoxy functionalizedgroups and cure compatibility groups, which retain their functionalityon the backbone of the acrylic copolymer. Preferably themulti-functionalized acrylic copolymer is a polar material due in partto the presence of the cure compatibility groups, which while not beingbound by any theory, is believed to aid in compatibility with the polararyl-containing, amino-functional silicone resin. This compatibility isbest seen by the reduction of haze in the cured coating composition. Asused herein, the use of the term “(meth)” followed by another term suchas acrylate refers to both acrylates and methacrylates. For example, theterm “(meth)acrylate” refers to either acrylate or methacrylate.Similarly, the term “(meth)acrylic acid” refers to methacrylic acid oracrylic acid. The acrylic copolymer is prepared via free radicalpolymerization in solvent, such as xylene, in which monomers,initiators, optionally chain transfer agents and solvent can be chargedinto a vessel and reacted at about 600 to 175° C. for about 1-6 hours toform the polymer. Typical solvents which can be used to prepare theacrylic copolymers are the following: toluene, ethyl acetate, butylacetate, acetone, methyl isobutyl ketone, methylethyl ketone, ethylalcohol, mineral spirits, ethylene glycol monoethyl ether acetate, andother aliphatic, cycloaliphatic and aromatic hydrocarbon, esters,ethers, ketones and alcohols which are conveniently used. Alternativelythe acrylic copolymer can be prepared through free radical emulsion orsuspension addition polymerization or by dispersion of a pre-formedpolymer under shear into an aqueous medium. Preferably, the acryliccopolymer of the present invention is solvent-borne.

Monomers suitable for the preparation of acrylic copolymers include(meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate,butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and combinationsthereof. Additional monomers may be used to prepare the acryliccopolymer including carboxylic acid monomers such as (meth)acrylic acidand itaconic acid, and salts thereof; sulfonic acid monomers such assodium styrene sulfonate and acrylamido-methyl-propane sulfonate andsalts thereof; and phosphoric acid monomers such asphosphoethylmethacrylate and salts thereof. Monomers such as styrene,acrylonitrile, acetoacetoxyethyl methacrylate (AAEM), and alkoxysilanefunctional (meth)acrylate, as well as monomers capable of impartingco-curable functionality such as glycidyl (meth)acrylates andhydroxyalkyl (meth)acrylates, may also be used in the preparation of theacrylic copolymer. In certain embodiments, it may be advantageous toincorporate into the acrylic copolymer small amounts of copolymerizedmulti-ethylenically unsaturated monomer groups, including allyl(meth)acrylate, diallyl phthalate, 1,4-butylene glycol di(meth)acrylate,1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate,and divinyl benzene. It may also be advantageous to incorporate suchmonomer groups non-uniformly into the polymer to form multiphase polymerparticles to create a core-shell, hemispherical, or occluded morphology.Chain transfer agents may be used to prepare these acrylic copolymers,examples of which include dodecylmercaptan, 2-mercaptoethanol,mercaptotrialkoxy silane, butylmercaptopropionate,methylmercaptopropionate, and mercaptopropionic acid. Initiators may beused to prepare these acrylic copolymers, examples of which includeperoxy and azo compounds.

The epoxy functionalized groups of the acrylic copolymer compriseglycidyl groups such as glycidyl methacrylate (GMA) or glycidylacrylate; with preference to GMA. The cure compatibility groups of theacrylic copolymer comprise monomer groups, in polymerized form, thatcontain one or more of alcohol (OH) functionality, a phenolic group, asilicone group such as with the monomer 3-(trimethoxysilyl)propylmethacrylate (MATS), a tertiary amine or an acid group that is eitherpendant to the backbone (as with acrylic monomers) or attached as an endgroup, such as where an OH functional chain transfer agent is used inthe polymerization. Preferably the cure compatibility group ishydroxyethyl (meth)acrylate (HEMA or HEA). Preferably the acryliccopolymer is synthesized from monomers including GMA, HEMA, methylmethacrylate (MMA), and 2-ethylhexyl acrylate (EHA).

The acrylic copolymer contains 30-80% glycidyl (meth)acrylate monomerunits by weight based on the weight of the total monomer units added toproduce the copolymer; preferably 40-60% glycidyl (meth)acrylatemonomer; and most preferably greater than 30% glycidyl (meth)acrylatemonomer on the bottom of the range. The acrylic copolymer contains up to20% cure compatibility group monomer units by weight based on the weightof the total monomer units added to produce the copolymer; preferably upto 10% cure compatibility group monomer units; preferably up to 8% curecompatibility group monomer units; and preferably greater than to 2%cure compatibility group monomer units, with a preferred range of 5 to10%. The upper bound of the cure compatibility group is determinedprimarily by the viscosity of the copolymer when incorporating HEMA withGMA functional groups. Theoretically it is possible to have a highercontent of cure compatibility groups when using other monomers such aswith the combination of HEA and glycidyl acrylate. The acrylic copolymercontains an epoxy equivalent weight (EEW) in the range of 200-600 g/molepoxy as determined in accordance with ASTM D1652; preferably with alower limit greater than 250 g/mol epoxy, more preferably greater than275 g/mol epoxy; and preferably with an upper limit less than 500 g/molepoxy, more preferably less than 450 g/mol epoxy; and with a preferredrange of 300-400 g/mol epoxy.

The acrylic copolymer has a calculated glass transition temperature(“Tg”) of eighty degrees Celsius (80° C.) or less, preferably 30° C. orless, most preferably 15° C. or less, with a preferred range of −40° C.to 10° C. The Tg is arrived at by selection of monomers and amounts ofmonomers to achieve the desired polymer Tg, as is well known in the art.Tgs of polymers are measured using Dynamic Scanning Calorimetry.

The acrylic copolymer solutions are viscous liquids with a viscosity inthe range of 500 centipoise (cP) to 8,000 cP at room temperature (25°C.) at around 70% solids. The acrylic copolymer of the present inventionhas a number average molecular weight of from 500 to 10,000 g/mol,preferably 1,000-5,000 g/mol or more, or, more preferably, 4,000 g/molor less, as measured by Gel Permeation Chromatography using polystyrenestandards.

Coating Composition Description

The coating composition of the present invention comprises the acryliccopolymer and the amino-functional silicone resin. The molar ratio ofamine NH functionality to epoxy functionality is in the range of from0.5 to 1.3; preferably 0.8 to 1. Preferably it is best to avoid anexcess of amine groups as this can lead to amine blush which is bad forexterior durability. Amine blush causes a loss of gloss upon exposure towater. The coating composition is typically subjected to ambient cure,though accelerated curing is possible.

The coating composition of the present invention may contain additionalcompositions including without limitation: accelerators/plasticizerssuch as benzyl alcohol, salicylic acid, andtris-2,4,6-dimethylaminomethyl phenol; fillers such as finely dividedminerals including silica, alumina, zirconia, talc, sulfates, TiO₂,carbon black, graphite, silicates and the like; other curing agents;other epoxy resins; reinforcing agents; rheology modifiers; solvents;accelerators; surfactants; ultra-violet (UV) stabilizers; antioxidants;wetting agents; solvents; defoamers; toughening agents; and colorantsincluding pigments, dyes, and tints.

Curable coating compositions of the present invention can beun-pigmented transparent clear coats, or pigmented systems for primer,basecoat and topcoat applications. The pigment may be any typicalorganic or inorganic pigment. Several different pigments may be neededto achieve a desirable color for a particular application. Examples ofsuitable pigments include without limitation, titanium dioxide, opaquepolymers, barytes, clay, calcium carbonate, red iron oxide, CI PigmentYellow 42, CI Pigment Blue 15, 15:1, 15:2, 15:3, 15:4 (copperphthalocyanines), CI Pigment Red 49:1, CI Pigment Red 57:1 and carbonblack.

The resulting coating compositions can be applied onto a substrate usingtechniques known in the art; e.g. by spraying, brushing, draw-down,roll-coating. The nominal dry film thickness (DFT) of the coating isgreater than or equal to 1 mil, preferably greater than or equal to 2mils, preferably greater than or equal to 2.5 mils and more preferablygreater than or equal to 3 mils. 1 mil equals 1/1000 of an inch.Examples of substrates that may be coated include without limitation,plastics, wood, metals such as aluminum, steel or galvanized sheeting,tin-plated steel, concrete, glass, composites, urethane elastomers,primed (painted) substrates, and the like. The coatings can be cured atroom temperature or at an elevated temperature in a forced air oven orwith other types of heating sources.

The following examples are illustrative of the invention.

EXAMPLES AND EXPERIMENTAL METHODS Acrylic Copolymers

Xylene was added to a 500 mL 4 neck round bottomed flask, equipped withstir shaft, condenser, thermocouple port and addition ports. A heatingmantle was used to bring the temperature of the xylene up to reflux(140° C.). A monomer blend consisting of glycidyl methacrylate (GMA),methyl methacrylate (MMA), 2-ethylhexyl acrylate (EHA), and2-hydroxyethyl methacrylate (HEMA) was weighed out and mixed in a 500 mLglass jar then divided equally into 50 mL plastic feed syringes withLuer Lock connectors. The initiator, tert-butylperoxyacetate (TBPA, 50%in mineral spirits) was added to a single 50 mL plastic syringe andconnected to feed tubing via the Luer Lock connection with long feedneedle attachment. A dual syringe pump was used to add monomer mix at aconstant feed rate and a single feed syringe pump was used to feed theinitiator. The feeds were initiated when the solvent was at reflux. Thefeed rate time and temperature are dependent on the solvent and thehalf-life of the initiator. Once feeds were depleted the lines wereflushed with small amount of solvent. Run was continued for anadditional hour to reduce residual monomer and initiator to acceptablelevels. Table 1 shows the acrylic copolymers made.

TABLE 1 Acrylic copolymers EEW g/mol EEW g/mol Tg epoxy, as epoxy, onAcrylic GMA MMA EHA HEMA TBPA xylene % solids ° C. measured solids A1 Wt% of 50 10 30 10 75% −3 400 300 monomer composition grams 150 30 90 3036 88 A2 Wt % of 50 15 35 0 72% −2 400 300 monomer composition grams 15045 105 0 36 88

Acrylic Copolymer Characterization GPC

Sample was dissolved 2 mg/mL in tetrahydrofuran (THF); solutions werefiltered through 0.2 μm PTFE syringe filter prior to injection.Molecular weight measurements were performed with GPC measured on anAgilent 1100 series with MIXED-D columns (300×7.5 mm) at a flow rate of1.0 mL/min at 35° C. Agilent refractive index detector is used byAgilent GPC/SEC software. Calibration is performed using 17 narrow PSstandards from Polymer labs, fit to a 3rd order polynomial curve overthe range of 3,742 kg/mol to 0.580 kg/mol.

EEW

EEW is measured in accordance with ASTM D1652. The epoxy resin isdissolved in methylene chloride and titrated with standardized 0.1Nperchloric acid (HClO4) in glacial acetic acid in the presence of excesstetraethyl ammonium bromide (TEAB) in acetic acid. Measurements wereperformed using a Metrohm 905 titrator and the associated Tiamotitration software configured for EEW determinations.

Percent Solids

Label the bottom of a small aluminum pan, place the pan on a scale andrecord its weight to the closest 0.0001 gram. Distribute approximately0.5 g-1.5 g of sample evenly in the pan using a pipette. Record thatweight as initial (pan+sample). Place on baking pan and clip down with abinder clip before putting sample in oven, cover resin with about 2grams of toluene using pipette, then carefully place in pre-heated ClassA oven. After 2 hours, remove baking pan and samples from the oven. Tarebalance and place sample (and pan) on balance and record final weight,and calculate the solids content by the formula:

Solids %=(Final weight−pan weight)/(initial weight−pan weight)*100

Glass Transition Temperature

The T_(g) was measured with Differential Scanning Calorimetry DSC Q2000V24.10 in accordance with ASTM D7426 with a sample size of about 5-10mg. The temperature profiles performed as followed: Isotherm at 10° C.for 5 minutes, Ramp to −50° C. @ 10° C./minute, isotherm for 5 minutes,ramp to 150° C. @ 10° C./minute, isotherm for 5 minutes, Tg was analyzedwith TA software.

Viscosity

Viscosity measurements were taken using the Brookfield DV-III Ultraviscometer with the Small Sample Adapter (SSA). The Small SampleAdapter's rheologically correct cylindrical geometry provides extremelyaccurate viscosity measurements and shear rate determinations. For thesesamples 9 mL of material was deposited into the cylinder and spindles#31 or #34 were used and the speed was varied to achieve a torque of ˜25Newton meters (N*m). Measurements were reported in unites of centipoises(cP).

Amino-Functional Silicone Resins

Amino-functional silicone resins S1 to S6 are shown in Table 2. ResinsS1-S4 incorporate aryl groups through SiOC grafting, resin S5incorporates aryl groups through SiC grafting and resin S6 does notincorporate aryl groups. Resins S1, S3 and S4 incorporate aminefunctionality through SiC bonds, while resins S2, S5 and S6 incorporateamine functionality through SiOC bonds. The procedures for producingresins S1-S6 are provided after Table 2.

TABLE 2 SiOC Resin Candidate SiC Amine SiC Aryl Amine SiOC Aryl S1Benzyloxy on Me-T, Aminopropyl- none none benzyl NH₂-T triethoxysilanealcohol S2 Benzyloxy on Me-T, none none 1-amino-2- benzyl SiOC NH₂propanol alcohol S3 secondary aryloxy on Aminopropyl- none nonesec-phenethyl Me-T, NH₂-T triethoxysilane alcohol S4 tertiary aryloxy onAminopropyl- none none 2-methyl-1- Me-T, NH₂-T triethoxysilane phenyl-2-propanol S5 DT^(Ph), SiOC NH₂ none Phenyltrimeth- 1-amino-2- noneoxysilane propanol S6 Me-T + amino- none none 1-amino-2- none propanolpropanolS1: D_(0.14)T^(NH2) _(0.22)T^(Me) _(0.64)(OBz)_(0.21), amine equivalentweight 261 g/eq NH, 37 mol % OMe, 20 mol % OEt

Reagents:

-   -   Methyltrimethoxysilane (MTM)—Mw=136.22    -   Dimethyldimethoxysilane—Mw=120.22    -   Aminopropyltriethoxysilane—Mw=221.37    -   Benzyl alcohol—Mw=108.14 g/mol; bp=205° C.

Procedure:

A 250 mL 2 neck round bottom flask was loaded with:

-   -   MTM (80.96 g, 0.594 mols, 1.783 mols OMe)    -   Dimethyldimethoxysilane (21.88 g, 0.182 mols, 0.364 mols OMe)    -   3-Aminopropyl Triethoxysilane, available from The Dow Chemical        Company as Dowsil™ Z-6011 (48.78 g, 0.220 mols, 0.660 mols OEt)    -   benzyl alcohol (22.25 g, 0.206 mols)        The flask was equipped with a magnetic stir bar and a Dean Stark        apparatus attached to a water-cooled condenser. The mixture was        compatible at room temperature. DI water (16.73 g, 0.929 mols)        was added slowly, starting at room temperature. Exotherm to        46° C. and then heated with an aluminum block at a pot        temperature of 65° C. for 1 hour. Then increase temperature and        distill off alcohols up to a pot temperature of 150° C. Amount        of volatiles removed: 73.65 g. Continued to heat at 150° C. for        5 hours. 1.65 g of volatiles were removed within the first hour.        No more collected after this time. Stripped product on a        rotovapor at an oil bath temperature of 120° C. and ˜1.5-2 mm        Hg. The product was a clear, colorless, viscous liquid at room        temperature. Isolated Yield: 100.5 g. Calculated amine        equivalent weight from ¹³C NMR spectrum: 261 g/mol NH. NMR        Analysis of product:        D_(0.136)T^(PrNH2) _(0.219)T^(Me) _(0.645), OZ content: 79.1 mol        % (OMe=36.6 mol %; OEt=19.7 mol %; OBz=21.2 mol %; OH=1.6 mol        %).        S2: T^(Me) _(0.99)(OBz)_(0.2)(OCH(CH₃)CH₂NH₂)_(0.18), amine        equivalent weight 297 g/eq NH, 32.5 mol % OZ)

Reagents:

-   -   Methyl-T Resin (as described below): D_(0.01)T^(Me) _(0.99)        FW=83.52 g/mol Si; OZ=71.77 mol % (OMe=70.30 mol %, OH=1.47 mol        %)    -   1-amino-2-propanol—Mw=75.11, bp=160° C.    -   Benzyl alcohol—Mw=108.14 g/mol, bp=205° C.    -   Xylenes—ACS grade

Procedure:

-   -   A 250 mL 2 neck round bottom flask was loaded with:        -   Methyl-T Resin (84.89 g, 1.016 mols Si, 0.729 mols OZ)        -   1-amino-2-propanol (16.52 g, 0.220 mols)        -   Benzyl alcohol (22.21 g, 0.205 mols)        -   Xylenes (36.67 g)            The flask was equipped with a magnetic stir bar and a Dean            Stark apparatus attached to a water-cooled condenser. The            amount of xylenes added would result in a theoretical yield            of 75 wt % in xylenes. Reaction mixture was initially hazy            at room temperature, but turned clear within 5 minutes at            room temperature. —theoretical amount of methanol that could            be produced if 100% of BzOH & amine reacted: 13.62 g. Heated            with an aluminum block at a pot temperature of 135° C. Start            time was measured from when volatiles first began to collect            in the Dean Stark apparatus which corresponded to a pot            temperature of 127° C. Allowed reaction to heat up to            135° C. and then held at this temperature. Total time: 12            hours. Volatiles removed: 30 min-3.81 g; 1 hr-6.28 g; 2            hrs-8.39 g; 3 hrs-10.06 g; 4 hrs-10.55 g; 5 hrs-10.77 g. No            more volatiles collected after 5 hours. Sample at 12 hrs was            analyzed by 13C NMR and showed ˜89% of the            1-amino-2-propanol had reacted onto silicon. ˜93% of the            benzyl alcohol had also reacted onto silicon.            Methyl-T Resin production: T^(Me) ₁ resin with target 75 mol            % OMe

Reagents:

-   -   Methyltrimethoxysilane—Mw=136.22    -   DI water    -   Trifluoromethanesulfonic acid, available from 3M as Fluorad™        FC-24—Mw=150.08 g/mol, density=1.696 g/ml    -   Calcium Carbonate powder≤50 um particle size, Mw=100.09 g/mol

Procedure:

A 1 L 4 neck round bottom flask was loaded with methylltrimethoxysilane(650.0 g, 4.772 mols Si, 14.315 mols OMe). Added FC24 (0.33 g, 192 uL).This amounts to 500 ppm. Added DI water (96.71 g, 5.368 mols) slowlystarting at room temperature. Exotherm to 64° C. Theoretical amount ofmethanol that could be produced: 344.0 g (assuming 100% hydrolysis andcondensation). Heated at 65° C. for 2 hours. Distilled off 320.88 g ofmethanol up to a pot temperature of 75° C. Added calcium carbonate (1.32g) to neutralize the FC24. This amounts to 4× the amount of FC24 added(on a weight basis). Mixed for 2 hours while cooling to roomtemperature. Stripped resin on a rotovapor. Oil bath temp=50° C., ˜50-60mm Hg. Pressure filtered through a 142 mm diameter Magna, Nylon,Supported, Plain, 0.45 Micron filter at room temperature. IsolatedYield: 394.0 g. Product was a clear, low viscosity liquid at roomtemperature. Molecular weight: Mn=1,837; Mw=2,838 (relative topolystyrene standards in THF). 29Si NMR Analysis of Product: D^(Me2)_(0.010)T^(Me) _(0.990), OZ=71.77 mol % (70.30 mol % OMe, 1.47 mol %OH), FW=83.52 g/mol Si. Methoxy content calculated from 13C NMR usingCDCl3 as an internal standard.S3: An amine siloxane resin with aryl groups added through SiOC using asecondary alcohol and amine functionality added through SiC bonds

Reagents:

-   -   Methyltrimethoxysilane (MTM)—Mw=136.22    -   Dimethyldimethoxysilane—Mw=120.22    -   Aminopropyltriethoxysilane—Mw=221.37    -   DL-sec-Phenethylalcohol (sPhEtOH)—Mw=122.17 g/mol, bp=203-205°        C.

Procedure:

A 250 mL 2 neck round bottom flask was loaded with:

-   -   MTM (77.25 g, 0.567 mols, 1.701 mols OMe)    -   Dimethyldimethoxysilane (20.88 g, 0.174 mols, 0.347 mols OMe)    -   Z-6011 (48.76 g, 0.220 mols, 0.660 mols OEt)    -   sec-phenethylalcohol (25.10 g, 0.205 mols)        The flask was equipped with a magnetic stir bar and a Dean Stark        apparatus attached to a water-cooled condenser. Mixture was        compatible at room temperature. Added DI water (16.17 g, 0.898        mols) slowly starting at room temperature. Exotherm to 43° C.        Heated with an aluminum block at a pot temperature of 65° C. for        1 hour. Increase temperature and distilled off alcohols up to a        pot temperature of 150° C. Amount of volatiles removed: 67.98 g.        Continued to heat at 150° C. for 10 hours. Volatiles removed: 1        hr-2.22 g; 2 hrs-3.57 g; 3 hrs-4.02 g; 4 hrs-4.22 g; 5        hrs-4.42 g. No more volatiles collected after 5 hours. Stripped        product on a rotovapor at an oil bath temperature of 120° C. and        ˜1.5-2 mm Hg. Results: Product was a clear viscous liquid with a        slight yellow tint at room temperature. Isolated Yield: 98.4 g.        Calculated amine equivalent weight from ¹³C NMR spectrum: 258        g/mol NH. NMR Analysis of product: D_(0.135)T^(PrNH2)        _(0.227)T^(Me) _(0.638); OZ content: 78.5 mol % (OMe=32.1 mol %;        OEt=23.9 mol %; sec-PhEtO=20.1 mol %; OH=2.4 mol %); 8.52 wt %        OMe; 9.18 wt % OEt; 20.8 wt % sec-PhEtO; 13.3 wt % Phenyl (from        sec-PhEtO) OR values calculated from 13C NMR data using CDCl3 as        an internal standard. Si molar fractions for T^(PrNH2) and        T^(Me) derived from 13C NMR data.        S4: An amine siloxane resin with aryl groups added through SiOC        using a tertiary alcohol and amine functionality added through        SiC bonds

Reagents:

-   -   Methyltrimethoxysilane (MTM)—Mw=136.22 g/mol    -   Aminopropyltrimethoxysilane—Mw=179.29    -   2-Methyl-1-Phenyl-2-Propanol—Mw=150.22, bp=215° C.    -   Xylenes—ACS grade    -   KOH (45% in water)—Mw=56.1 g/mol    -   HCl solution—Diluted 8.0N HCl in water in methanol resulting in        a solution containing 0.000742 mols HCl/gram

Procedure:

A 250 mL 2 neck round bottom flask was loaded with:

-   -   MTM (97.01 g, 0.712 mols, 2.136 mols OMe)    -   Aminopropyltrimethoxysilane (39.40 g, 0.22 mols, 0.659 mols OMe)    -   2-Methyl-1-Phenyl-2-Propanol (39.85 g, 0.265 mols)        The flask was equipped with a magnetic stir bar and a Dean Stark        apparatus attached to a water-cooled condenser. Added 1.8×        MePhPrOH. Added DI water (17.14 g, 0.951 mols) slowly starting        at room temperature. Exotherm to 50° C. Heated with an aluminum        block at a pot temperature of 65° C. for 1 hour. Hazy the entire        time. Increase temperature and distilled off methanol up to a        pot temperature of 95° C. Amount of volatiles removed: 53.9 g.        Diluted to ˜75% with xylenes (36.67 g). Clear. With mixing added        a solution containing (0.122 g of 45% KOH (aq) in 1 g of        methanol) at room temperature. This amount of KOH amounts to        ˜500 ppm based on the theoretical yield. Heated with an aluminum        block. Start time was measured from when volatiles first began        to collect in the Dean Stark apparatus which corresponded to a        pot temperature of 91° C. Allowed to heat up to 115° C. and then        left at this temperature. Volatiles removed: 30 min=9.32 g; 1        hr=10.72 g; 2 hrs=11.86 g; No more volatiles collected afte 2        hours. Total time=12 hrs. 13C NMR analysis of 5 hr sample showed        ˜35% of MePhPrOH had reacted onto silicon. 13C NMR analysis of        12 hr sample showed ˜46% of MePhPrOH had reacted onto silicon.        At room temperature added HCl solution (1.38 g of solution).        Stoichiometry 1.05 mols HCl: 1.0 mols KOH. Mixed overnight at        room temperature. Stripped product on a rotovapor at an oil bath        temperature of 120° C. and ˜2 mm Hg. Pressure filtered through        an Osmonics MAGNA Nylon Supported Plain 0.45 um filter (47 mm        diameter) at room temperature. Filtration rate was slow. Only        filtered 80-90% of the material.        Results: Product was a clear, light yellow, viscous liquid at        room temperature. Isolated Yield: 91.3 g. Calculated amine        equivalent weight from ¹³C NMR spectrum: 229 g/mol NH. NMR        Analysis of product: T^(PrNH2) _(0.233)T^(Me) _(0.767); OZ        content: 63.8 mol %; (51.3 mol % OMe, 12.5 mol % MePhPrO); 17.5        wt % MePhPrO; 9.1 wt % Phenyl (from MePhPrO); Si molar ratios        and OR values derived from 13C NMR data.        S5: DTPh resin reacted with amino-propanol

Reagents:

-   -   Dowsil™ 3074, available from The Dow Chemical        Company—D_(0.337)T^(Cyclohexyl) _(0.010)T^(Ph) _(0.653);        OZ=68.64 mol %; FW-126.5 g/mol Si    -   1-amino-2-propanol—Mw=75.11, bp=160° C.

Procedure:

A 250 mL 1 neck round bottom flask was loaded with: Dowsil™ 3074 (94.19g, 0.745 mols Si. 0.511 mols OZ) and 1-amino-2-propanol (16.52 g, 0.220mols, 0.440 mols NH). The flask was equipped with a magnetic stir barand a Dean Stark apparatus attached to a water-cooled condenser. Mixturewas not compatible at room temperature. Heated at an aluminum blocktemperature of 140° C. for 2 hours. Amount of volatiles collected in 1sthour was 3.35 g and in the 2nd hour was 0.31 g. The reaction mixtureturned clear while heating to 140° C. Increased block temperature to180° C. Held at this temperature for 2 hours. Amount of volatilescollected in 1st hour was 1.85 g and in the 2nd hour was 0.13 g.Stripped product on a rotovapor at an oil bath temperature of 115° C.and ˜1 mm Hg.Results: Product was a clear viscous liquid at room temperature.Isolated Yield: 100.9 g. Calculated amine equivalent weight from ¹³C NMRspectrum: 256 g/mol NH. NMR Analysis of product: D_(0.333)T^(Cyclohexyl)_(0.007)T^(Ph) _(0.660); OZ content: 61.95 mol % 26.9 mol % OR; 33.5 mol% OMe. The above two OR values were calculated from 13C NMR by takingthe ratio of the OR integral value and dividing that by the integralvalue of phenyl groups.S6: Me-T resin reacted with 1-amino-2-propanol without arylfunctionality

Reagents:

-   -   Dowsil™ CF-2403 Methyl-T Resin, available from The Dow Chemical        Company—D_(0.015)T^(Me) _(0.985) FW=93.4 g/mol Si; OMe=113.6 mol        %    -   1-amino-2-propanol—Mw=75.11, bp=160° C.

Procedure:

A 250 mL 2 neck round bottom flask was loaded with Dowsil™ CF-2403 (80.0g, 0.857 mols Si, 0.973 mols OMe) and 1-amino-2-propanol (14.47 g, 0.193mols). The flask was equipped with a magnetic stir bar, a nitrogenblanket was applied, and a Dean Stark apparatus was attached to awater-cooled condenser. Reaction mixture was hazy at room temperature.Heated with an aluminum block. Start time was measured from whenvolatiles first began to collect in the Dean Stark apparatus whichcorresponded to a pot temperature of 101° C. Allowed to heat up to 125°C. and then held at this temperature. Total time=4 hrs. Reaction mixtureturned clear at ˜60° C. during heating up. Volatiles removed: 30min-5.97 g; 1 hr-6.00 g. No more volatiles collected after 1 hour.Stripped product on a rotovapor at an oil bath temperature of 70° C. and˜2 mm Hg.Results: Product was a clear low viscosity liquid at room temperature.Yield: 76.4 g. Calculated amine equivalent weight from ¹³C NMR spectrum:241 g/mol NH. The amine equivalent weight was calculated from 13C NMRdata using the average of 2 carbons (˜20 ppm & ˜70 ppm) in the 13C NMRspectra and using CDCl3 as an internal reference. Integral values (9.38& 8.62). NMR Analysis of product: D_(0.010)T^(Me) _(0.990) Total OZcontent: 100.3 mol % (20.6 mol % OR; 79.7 mol % OMe)OR=1-amino-2-propanol reacted onto silicon.

Coating Formulation: Clear Coatings

The clear coating compositions of Table 3 were prepared by the followingmanner: the acrylic copolymer was placed in a MAX 40 SpeedMixer™ cup andthe amino-functional silicone resin was added and mixed for 2 minutes at2000 rpm in FlackTek™ DAC150 SpeedMixer™. In formulating the coatingcompositions, the acrylic copolymer and amino-functional silicone resinare added in an amount to provide an epoxy/NH molar ratio of 1:1.

TABLE 3 Silicone Coating Coating Acrylic Silicone Resin Optical CoatingExample Copolymer Resin Description Quality Tg (° C.) CTG 1 A1 S1 SiCAmine, Clear 49.4 SiOC Aryl CTG 2 A1 S2 SiOC Amine, Clear 45.5 SiOC ArylCTG 3 A1 S3 SiC Amine, Slightly Not SiOC s-Aryl Cloudy tested CTG 4 A1S4 SiC Amine, Clear Not SiOC t-Aryl tested CTG 5 A1 S5 SiOC Amine,Slightly 49.2 SiC Aryl Cloudy CTG 6 A1 S6 SiOC Amine, Milky Not no ArylCloudy tested CTG 7 A2 S1 SiC Amine, Clear Not SiOC Aryl tested CTG 8 A2S2 SiOC Amine, Slightly Not SiOC Aryl Cloudy testedCoating Tg was determined after 10 days of moisture cure, measured usingDSC (1^(st) heating at 20° C./min).Comparisons of CTG 1, CTG 2 and CTG 5 in Table 2 illustrate the benefitsof the present invention. CTG 1 contains 21 mole % of phenyl groups, CTG2 contains 22 mole % of phenyl groups and CTG 5 contains 66 mole % ofphenyl groups. Although comparative CTG 5 contains a higher mol % ofphenyl groups than CTG 1 or CTG 2, and incorporates these groups throughSiC bonds, cloudy coatings result which will translate into inferiorproperties. CTG 1 and CTG 2 show that incorporation of phenyl groupsthrough SiOC bonds can offer high quality, optically clear coatings evenwith aryl group incorporation amounts that are lower than the SiC bondedversion. The industrial applicability of the present invention cannot beunderstated considering the low cost of SiOC based resins as compared toSiC based resins.

Draw Down Application Method for Clear Coat Applications

A coating was applied to Q-Panel R-412-I (phosphate treated cold rolledsteel) and AL 412 (chromate treated aluminum) panels according to ASTMD4147. The panel was secured on a firm horizontal surface using amagnetic chuck or clamp. A multiple clearance square applicator was usedto apply coating to the panel, 5 to 6 mil wet thickness was targeted toachieve the desired dry film thickness of ˜2.5 mils.

Coating Application and Test Methods Drawdown Procedure

A coating was applied to metal panels according to ASTM D4147-99(2007).The panel was secured on a firm horizontal surface using a magneticchuck. An ample amount of coating was poured across the top end of thepanel and 5 mil gap wet film applicator is used to draw down the coatingwith uniform pressure and speed along the length of the panel toward theoperator to apply a uniform film. Panels were allowed to cure in the labat a controlled temperature and humidity of 72° F. and 50% relativehumidity.Dry Time: Coatings were drawn down onto 1″×12″ glass substrates with awet film thickness of 76 micrometers (μm) and set on a BYK drying timerecorder. The set-to-touch, tack-free time, and dry hard were measuredby dragging a needle through the coating using a BYK drying timerecorder according to ASTM D5895-03.Pendulum Hardness: Pendulum hardness was measured using a PendulumHardness Tester from BYK Gardner equipped with a König pendulum. Thetester was run according to ISO 1522 and set to measure hardness inseconds.

Pencil Hardness

The pencil hardness of a coating film is measured according to the ASTMD3363 method.

A coating composition is applied on a glass panel to form a 120 micronthick wet film and cured at room temperature for 7 days. The resultantfilm is then tested by a Zhonghua pencil. The hardness of the pencilused is: 9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H, H, F, HB, B, 2B, 3B, 4B, 5B,6B, where 9H is the hardest, 6B is the softest Gloss: The 20°, 60°, and85° gloss of the coatings were measured according to ASTM D-523-89 usinga micro-TRI-gloss meter from BYK Gardner.

Methyl Ethyl Ketone Double Rub Test: The methyl ethyl ketone (MEK)double rub test was performed according to ASTM D5402 using thesemi-automatic MEK Rub Test machine made by DJH DESIGNS INC. The testingcontinued until the coating was rubbed through to the substrate or amaximum of 200 double rubs were completed without breakthrough.

The performance characteristics of the coating compositions are shown inTable 4. Ctg 1 and Ctg 2 as compared to Ctg 7 and Ctg 8 respectively,illustrate the importance of a cure compatibility group (e.g. HEMA) inthe acrylic copolymer to provide improved pencil hardness, improved drytime, improved gloss readings, improved hardness and improved MEKResistance.

TABLE 4 CTG 2 CTG 1 CTG 8 CTG 7 BY6063-3 BY6063-4 BY6063-10 BY6063-11Dry times (hr) Set-to-Touch 0.4 0.8 0.5 0.6 Tack-Free 1 2 6 6 Dry-Hard 25 18 9 Dry-Through 9 6 >24 16 Gloss 20° Degree 74 74 10 36 Average 60°Degree 95 94 37 78 Average Thickness 3.1 2.5 2.4 2.1 Average (mils)Konig Hardness [sec] 1 Day 28 35 14 13 7 Day 87 73 30 17 MEKResistance >200 >200 198 50 [double rubs] Pencil F HB 2B 5B

1. A curable coating composition comprising: (1) an amino-functionalsilicone resin comprising in polymerized form, structural units of: (i)(R₃SiO_(1/2))_(a); (ii) (R₂Si(OR′)_(x)O_((2-x)/2))_(b); (iii)(RSi(OR′)_(y),O_((3-y)/2))_(c); and (iv) (Si(OR′)_(z)O_((4-z)/2))_(d)wherein each R′ is independently hydrogen, an alkyl group, afunctionalized alkyl group, an aryl group or a functionalized arylgroup, provided that at least 10 mole percent of all R′ groups are arylgroups or functionalized aryl groups; wherein each R is independentlyhydrogen, an alkyl group, or a functionalized alkyl group; wherein atleast 10 mole percent of the combination of R and R′ groups are aminecontaining groups of the formula: —R_(a)—NHR_(b) where R_(a) is an alkylgroup or an aryl-containing group derived from an amino alcohol andR_(b) is hydrogen or an alkyl group; wherein a+b+c+d=1.00 (100 molepercent); x is either 0 or 1; y is either 0, 1 or 2; and z is either 0,1, 2, or 3; and the —NH— equivalent mass of the amino-functionalsilicone resin is from 50 to 750; and (2) an acrylic copolymer whichhas, in polymerized form, epoxy functionalized groups and curecompatibility groups; and wherein the coating composition has a molarratio of amine NH functionality to epoxy functionality in the range offrom 0.5 to 1.3.
 2. The coating composition of claim 1 having a molarratio of amine NH functionality to epoxy functionality in the range offrom 0.8 to
 1. 3. The coating composition of claim 1 wherein at least 20mole percent of the combination of R and R′ groups of theamino-functional silicone resin are amine containing groups of theformula: —R_(a)—NHR_(b).
 4. The coating composition of claim 1 whereinfrom 5 to 42 mole percent of the combination of R and R′ groups of theamino-functional silicone resin are amine containing groups of theformula: —R_(a)—NHR_(b).
 5. The coating composition of claim 1 whereinthe amino alcohol is selected from the group which (a) has sterichindrance around the COH moiety; (b) is a secondary or tertiary alcohol;or (c) mixtures thereof.
 6. The coating composition of claim 1 whereinthe amino alcohol is 1-amino-2-propanol or 1-amino-2-methylpropan-2-ol.7. The coating composition of claim 1 wherein from 20 to 50 mole percentof all R′ groups are aryl groups or functionalized aryl groups.
 8. Thecoating composition of claim 1 wherein the epoxy functionalized groupsof the acrylic copolymer are derived from one or more monomers selectedfrom the group of glycidyl maethacrylate (GMA), glycidyl acrylate, andmixtures thereof; and wherein the acrylic copolymer has an epoxyequivalent weight (EEW) in the range of 200-600.
 9. The coatingcomposition of claim 8 wherein the acrylic copolymer comprises inpolymerized form, 30-60% glycidyl (meth)acrylate monomer units by weightbased on the weight of the total monomer units of the acrylic copolymer.10. The coating composition of claim 1 wherein the acrylic copolymercomprises in polymerized form, from 2% to 20% cure compatibility groupmonomer units by weight based on the weight of the total monomer unitsof the acrylic copolymer.
 11. The coating composition of claim 1 whereinthe cure compatibility groups of the acrylic copolymer comprise monomergroups, in polymerized form, that contain one or more of alcohol (OH)functionality, a phenolic group, a tertiary amine or an acid group thatis either pendant to the backbone or attached as an end group.
 12. Thecoating composition of claim 1 wherein the cure compatibility group isderived from hydroxyethyl methacrylate (HEMA).
 13. A coated articlecomprising one or more layers of a cured coating composition of claim 1.